1. Technical Field
The invention relates to fire monitors for projecting water long distances for extinguishing fires. In particular, although not exclusively, the invention relates to fire monitors to be mounted on fire-fighting vessels for use in extinguishing fires on oil-rig platforms.
2. Background of Invention
Fire monitors currently in use comprise a water conduit, inlet means connected to the water conduit, and an outlet nozzle connected to the water conduit. Maximum jet throw in fire monitors of this construction is dependent on good inlet conditions to the outlet nozzle and so it is advantageous that flow into the nozzle is free of swirl and of low turbulence level. The water conduit may therefore be provided with flow straightening vanes. However, the inlet means normally comprise bends in two planes in the form of a "ram's horn" inlet. These bends cause swirl which should be dissipated by the straightening vanes, but in practice insufficient space is available for straightening out the flow after the bends and for reducing turbulence levels. The result is poor performance in terms of water jet throw distance. Difficulty is therefore encountered when attempting to scale up existing designs of fire monitors in order to obtain the long distance water jet throw that has now become necessary.